POS1145 PREDICTORS OF FRACTURE IN PATIENTS WITH NORMAL BONE DENSITY, AN OBSERVATIONAL STUDY
Authors: J. Malcolm, Z. Sultan, M. Bukhari
Journal: Annals of the Rheumatic Diseases (2022)

Background Although most fragility fractures occur in osteoporotic patients, fractures of the lumbar spine and the femora are also common in patients with normal bone mineral density (BMD). A number of risk factors are known to be associated with fractures in patients with reduced BMD. However, risk factors for fractures in patients with normal BMD remain relatively unexplored. Objectives Evaluate the risk factors associated with fractures in patients with a normal BMD (T-score ≥ -1.00) in the lumbar spine and right and left femur in an observational cohort Methods Data was collected from patients attending a District General Hospital in the Northwest of England for a DEXA scan between 2004 to 2019. Patients with a T-score ≥-1.00 in L1-4 and the right and left femur were included. Chi-squared test and Student’s t-test were used to compare risk factors in patients with and without fractures. A series of logistic regression models that adjusted for age and sex were then fitted to determine risk factors associated with a fracture. Area under the ROC curve was calculated for each model. Ethical approval was obtained from the Northwest Regional Ethics Committee. Results 6,504 patients were included in analysis, 1,491 (22.9%) of whom had a fracture. Mean age (SD) at scan was 58.64 (12.98) years and 5,347 (82.2%) were female. Risk factors and their association with fracture occurrence after adjusting for age and sex are shown in Table 1. Weight, BMI, and current alcohol use were statistically significantly (p &lt;0.05) associated with increased risk of fracture. History of Rheumatoid Arthritis, steroid use, and increased T-score in L1-4 or the right or left femur were statistically significantly (p &lt;0.05) associated with decreased risk of fracture. Table 1. Logistic regression with adjustment for age and sex Characteristic Odds ratio (95% confidence interval ) P-value AUC Height, cm 1.006 (0.997, 1.016) 0.176 0.5666 Weight, kg 1.010 (1.007, 1.014) 0.000 0.5804 BMI 1.027 (1.016, 1.037) 0.000 0.5773 Current smoker 1.164 (0.975, 1.389) 0.094 0.5664 Previous smoker 1.120 (0.976, 1.284) 0.106 0.5672 Current excess alcohol use 1.299 (1.033, 1.634) 0.025 0.5668 Pervious excess alcohol use 1.441 (0.943, 2.202) 0.091 0.5664 History of Rheumatoid Arthritis 0.674 (0.520, 0.874) 0.003 0.5708 Current steroid use 0.498 (0.406, 0.611) 0.000 0.5911 Previous steroid use 0.796 (0.669, 0.946) 0.010 0.5682 Mean T-score L1 0.929 (0.880, 0.980) 0.007 0.5698 Mean T-score L2 0.917 (0.874, 0.961) 0.000 0.5734 Mean T-score L3 0.906 (0.868, 0.947) 0.000 0.5758 Mean T-score L4 0.925 (0.889, 0.962) 0.000 0.5734 Mean T-score left neck of femur 0.866 (0.803, 0.933) 0.000 0.5662 Mean T-score total left femur 0.839 (0.780, 0.902) 0.000 0.5710 Mean T-score right neck of femur 0.847 (0.785, 0.914) 0.000 0.5672 Mean T-score total right femur 0.839 (0.779, 0.904) 0.000 0.5723 Conclusion In the FRAX tool, increased weight is considered protective against fractures, and steroid use and Rheumatoid Arthritis are thought to increase fracture risk. In our cohort of patients with normal BMD, patients with increased weight had a higher risk of fracture, and patients with Rheumatoid Arthritis and steroid use had a decreased fracture risk. While there is overlap in the risk factors associated with fractures in patients with reduced BMD and normal BMD, our study suggests that some characteristics protective of fractures in osteoporotic patients may increase the risk of fracture in patients with a normal BMD. References [1]Siris ES, et al. Arch Intern Med 2004; 164: 1108-1112. www.sheffield.ac.uk/FRAX/ Disclosure of Interests None declared